This interdisciplinary project will explore the role of spirituality and religiousness in the adjustment of midlife and older aged patients following cardiac surgery. It has been speculated that the effectiveness of religious practice can be associated with a placebo effect, hope, optimism, and sense of control, yet few empirical tests have demonstrated the mediating effect of these psychological factors. The present study thus attempts to make conceptual distinctions among these relationships by evaluating constructs simultaneously. Specifically, we seek to advance knowledge of the multifactorial determinants of adjustment and to test the hypothesis that the spiritual experience and private religiousness will predict better adjustment with a lower level of depression, distress, and fatigue, through mediating psychological factors. Data from 300 patients (aged 40 and above) at the University of Michigan Medical Center will be gathered through face- to-face interview at one month pre-surgery, during hospitalization, and one month post-surgery. Standardized instruments will be employed as well. A hospital computerized database will provide physical, medical, and surgical data and demographic information. Structural equation modeling and regression analyses will be utilized for assessing major research questions and testing the primary hypothesis. The proposed research will enhance our understanding of possible mechanisms concerning the spiritual dimension in cardiac rehabilitation through sophisticated methodological and data-analytic strategies. The ultimate goal is to improve the quality of patients' lives through better hospital care and postoperative management.